Human anti-VEGFR-2/KDR antibodies

ABSTRACT

The invention relates to antibodies that bind to VEGFR-2. The antibodies are used for treating neoplastic diseases, hyperproliferative disorders, and angiogenic disorders and can be used alone or in combination with other agents.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a 371 of PCT/US2015/054569, filed Oct. 7, 2015,which claims the benefit of priority to U.S. Application No. 62/061,097,filed on Oct. 7, 2014, which are incorporated herein by reference intheir entireties. This application also relates to PCT/US2013/063754,filed Oct. 7, 2013, and to U.S. Ser. No. 61/710,420, filed Oct. 5, 2012,both of which are incorporated herein by reference in their entireties

FIELD OF THE INVENTION

The invention relates to antibodies that bind to VEGFR-2. The antibodiesare used for treating neoplastic diseases and hyperproliferativedisorders, and can be used alone or in combination with other agents.

BACKGROUND OF THE INVENTION

Angiogenesis is a highly complex process of developing new blood vesselsthat involves the proliferation and migration of, and tissueinfiltration by capillary endothelial cells from pre-existing bloodvessels, cell assembly into tubular structures, joining of newly formingtubular assemblies to closed-circuit vascular systems, and maturation ofnewly formed capillary vessels.

Angiogenesis is important in normal physiological processes includingembryonic development, follicular growth, and wound healing. Undueangiogenesis also leads to neovascularization in neoplastic diseases,and in non-neoplastic diseases such as age-related macular degeneration(AMD), diabetic retinopathy, and neovascular glaucoma. Anti-angiogenictherapy that targets vascular endothelial growth factor (VEGF) withranibizumab (Lucentis®) has been shown to be effective in delayingprogression of AMD. However, neovascularization is complex and multipleangiogenic mechanisms are likely to contribute. There remains a need todevelop agents and therapies for treating diseases associated withneovascularization.

SUMMARY OF THE INVENTION

The present invention provides human antibodies, and fragments thereofthat bind to VEGFR-2 (KDR). In some embodiments, the antibodies blockligand binding (e.g., one or more of VEGF-A, VEGF-C, VEGF-D, or VEGF-E)to VEGFR-2. In some embodiments, the antibodies neutralize activation ofVEGFR-2. The antibodies are used for treating neoplastic diseases,including, for example, solid and non-solid tumors, andhyperproliferative disorders. Accordingly, the invention providesmethods of neutralizing the activation of KDR, methods of inhibitingtumor growth, including inhibition of tumor associated angiogenesis, andmethods of treating angiogenesis related disorders. The presentinvention provides kits having human antibodies or antibody fragmentsthat bind to VEGR receptors.

In one embodiment, the invention provides an isolated antibody orfragment thereof that binds to human VEGFR2, comprising a heavy chainvariable domain, which comprises a CDR1, a CDR2, and a CDR3 sequence,wherein:

(i) the CDR1 sequence is GFTFSWYVMG, (SEQ ID NO: 237)(ii) the CDR2 sequence is selected from the group consisting ofSIYPQGGATSYADSVKG, (SEQ ID NO: 238) SIYPQGGATNYADSVKG, (SEQ ID NO: 239)and SIYPSGGATNYADSVKG; (SEQ ID NO: 240) and(ii) the CDR3 sequence selected from the group consisting of GNYFDY,(SEQ ID NO: 241) GNYLDY, (SEQ ID NO: 242) GPYLDY (SEQ ID NO: 243) andGSYLDY, (SEQ ID NO: 244)with the proviso that the heavy chain variable domain does not compriseboth the CDR2 sequence of SEQ ID NO: 240 and the CDR3 sequence of SEQ IDNO: 241.

In one embodiment, the invention provides an isolated antibody orfragment thereof that binds to human VEGFR2, comprising a light chainvariable domain, which comprises a CDR1, a CDR2, and a CDR3 sequence,wherein

(i) the CDR1 sequence is RASQSVSSNYFG, (SEQ ID NO: 245)(ii) the CDR2 sequence is GASSRAT, (SEQ ID NO: 246) and(iii) the CDR3 sequence is selected from the group consisting ofQQFDSLPLT, (SEQ ID NO: 247) QQHDSSPLS, (SEQ ID NO: 248) QQFDSSPLS,(SEQ ID NO: 249) and QQFDSSPLT. (SEQ ID NO: 250)

In one embodiment of the invention, the CDR2 of the heavy chain variabledomain has the sequence SIYPQGGATSYADSVKG (SEQ ID NO: 238), and the CDR3of the heavy chain variable domain has the sequence GNYFDY (SEQ ID NO:241).

In one embodiment of the invention, the CDR3 of the light chain variabledomain has the sequence QQFDSLPLT (SEQ ID NO: 247).

In one embodiment of the invention, the heavy chain variable domain hasa sequence that is selected from the group consisting of

(SEQ ID NO: 200) EVQLLESGGGLVQPGGSLRLSCAASGFTFSWYVMGWVRQAPGKGLEWVSSIYPQGGATSYADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCARGN YFDYWGQGTLVTVSS,(SEQ ID NO: 208) EVQLLESGGGLVQPGGSLRLSCAASGFTFSWYVMSWVRQAPGKGLEWVSSIYPQGGATNYADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCARGN YFDYWGQGTLVTVSS,(SEQ ID NO: 216) EVQLLESGGGLVQPGGSLRLSCAASGFTFSWYVMGWVRQAPGKGLEWVSSIYPSGGATNYADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCARGN YLDYWGQGTLVTVSS,(SEQ ID NO: 224) EVQLLESGGGLVQPGGSLRLSCAASGFTFSWYVMGWVRQAPGKGLEWVSSIYPSGGATNYADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCARGP YLDYWGQGTLVTVSS, and(SEQ ID NO: 232) EVQLLESGGGLVQPGGSLRLSCAASGFTFSWYVMGWVRQAPGKGLEWVSSIYPSGGATNYADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCARGS YLDYWGQGTLVTVSS.

In one embodiment of the invention, the light chain variable domain hasa sequence that is selected from the group consisting of

(SEQ ID NO: 204) DIQMTQSPGTLSLSPGEGATLSCRASQSVSSNYFGWYQQKPGQAPRLLIYGASSRATGIPDRFSGSGSGTDFTLTISRLEPEDSAVYYCQQFDSLPLTFG GGTKVEIKR,(SEQ ID NO: 212) DIQMTQSPGTLSLSPGEGATLSCRASQSVSSNYFGWYQQKPGQAPRLLIYGASSRATGIPDRFSGSGSGTDFTLTISRLEP EDSAVYYCQQHDSSPLSF GGGTKVEIKR,(SEQ ID NO: 220) DIQMTQSPGTLSLSPGEGATLSCRASQSVSSNYFGWYQQKPGQAPRLLIYGASSRATGIPDRFSGSGSGTDFTLTISRLEPEDSAVYYCQQFDSSPLSFG GGTKVEIKR,(SEQ ID NO: 228) DIQMTQSPGTLSLSPGEGATLSCRASQSVSSNYFGWYQQKPGQAPRLLIYGASSRATGIPDRFSGSGSGTDFTLTISRLEP EDSAVYYCQQFDSSPLTF GGGTKVEIKR, and(SEQ ID NO: 236) DIQMTQSPGTLSLSPGEGATLSCRASQSVSSNYFGWYQQKPGQAPRLLIYGASSRATGIPDRFSGSGSGTDFTLTISRLEP EDSAVYYCQQFDSSPLTF GGGTKVEIKR.

In one embodiment of the invention, the heavy chain variable domain hasa sequence that is

(SEQ ID NO: 200) EVQLLESGGGLVQPGGSLRLSCAASGFTFSWYVMGWVRQAPGKGLEWVSSIYPQGGATSYADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCARGN YFDYWGQGTLVTVSS,and the light chain variable domain has a sequnce that is

(SEQ ID NO: 204) DIQMTQSPGTLSLSPGEGATLSCRASQSVSSNYFGWYQQKPGQAPRLLIYGASSRATGIPDRFSGSGSGTDFTLTISRLEPEDSAVYYCQQFDSLPLTFG GGTKVEIKR.

In one embodiment of the invention, the antibody or fragment has isotypeIgG.

In one embodiment of the invention, the antibody or fragment is an scFv,Fv, Fab′, Fab, F(ab′)2, or diabody.

In one embodiment of the invention, the the antibody or fragment bindsto human VEGFR2 and murine hVEGFR2.

The present invention provides an isolated nucleic acid encoding theantibody or fragment of the present invention.

The present invention provides a nucleic acid vector comprising anisolated nucleic acid encoding the antibody or fragment of the presentinvention.

The present invention provides a prokaryotic or eukaryotic host cellcomprising an isolated nucleic acid encoding the antibody or fragment ofthe present invention.

The present invention provides a composition comprising an antibody orfragment of the present invention, and a pharmaceutically acceptablecarrier.

The present invention provides a method of neutralizing activation ofhuman VEGFR2 or murine VEGFR2 comprising contacting a cell with aneffective amount of an antibody or fragment of the present invention.

The present invention provides a method of inhibiting angiogenesiscomprising administering to a subject an effective amount of an antibodyor fragment of the present invention.

The present invention provides a method of reducing tumor growthcomprising administering to a subject an effective amount of an antibodyor fragment of the present invention.

The present invention provides a method of treating a neoplasticdiseases in a subject, comprising administering to a subject aneffective amount of an antibody or fragment of the present invention,wherein the neoplastic diseases is selected from the group consitring oflung cancer, colorectal cancer renal cell carcinoma, glioblastoma,ovarian cancer, bladder cancer, gastric cancer, multiple myeloma,non-small cell lung cancer and pancreatic cancer.

In one embodiment of the invention, the method which further comprisesadministering to a subject an effective amount of an epidermal growthfactor receptor (EGFR) antagonist.

In one embodiment of the invention, the method which further comprisesadministering to a subject an effective amount of an fms-like tyrosinekinase receptor (flt-1) antagonist.

In one embodiment of the invention, the method which further comprisesadministering to a subject an effective amount of a rho associatedkinase 2 (ROCK2) antagonist.

In one embodiment of the invention, the method which further comprisesadministering to a subject an effective amount of a matrixmetalloproteinase antagonist.

In one embodiment of the invention, the method which further comprisesadministering to a subject an effective amount of a PDGFRβ antibody.

In one embodiment of the invention, the method which further comprisesadministering to a subject an effective amount of a PD-L1 antibody.

In one embodiment of the invention, the patient is a human.

BRIEF DESCRIPTION OF THE FIGURES

FIGS. 1A-C show human heavy chain, lambda light chain, and kappa lightchain variable region sequences, respectively, of anti-VEGFR2 antibodiesof the invention identified by phage display.

FIG. 2 shows binding of antibodies of the invention to hVEGFR2 (top) anda construct containing domains 2 and 3 of hVEGFR2 (middle). The bottompanel shows ligand (VEGF₁₆₅) blocking.

FIG. 3 shows Mabs 101 and 102 of the invention inhibit VEGFA-stimulatedphosphorylation of VEGFR2, AKT, and MAPK in porcine aortic endothelial(PAE) cells overexpressing KDR (human VEGFR2).

FIG. 4 shows binding to hVEGFR2 and VEGF₁₆₅ ligand blocking by Mabs 104,105, 106, and 108. Similar results were obtained for Mabs 103, 107, 109,and 110 in a separate experiment. These Mabs contain the heavy chainvariable domain of Mab101, recombined with different light chainvariable domains.

FIG. 5 shows Mabs 105 and 106 of the invention inhibit VEGFA-stimulatedphosphorylation of VEGFR2 (KDR, FIG. 5A), p44/42 MAPK (FIG. 5B), and AKT(FIG. 5C) in porcine aortic endothelial (PAE) cells overexpressing KDR(human VEGFR2).

FIG. 6A depicts heavy chain amino acid sequences of five affinitymatured antibodies derived from Mab 138, which contains the V_(H) domainhaving SEQ ID NO:4 (sequence as shown in this Figure). FIG. 6B depictslight chain amino acid sequences of the same five affinity maturedantibodies derived from SEQ ID NO:160 (sequence as shown in thisFigure).

FIG. 7A depicts binding of antibodies of the invention to soluble humanand murine VEGFR2 compared to DC101 (a murine monoclonal Ab that bindsto murine VEGFR2) and a control antibody that binds only to humanVEGFR2. Mab 147 binds to both human and murine VEGFR2. Mab 106 binds tohuman VEGFR2 but not murine VEGFR2. FIG. 7B depicts data from ligandblocking experiments. Mab 147 blocks the binding of human VEGF withhuman VEGFR2 and the binding of murine VEGF with murine VEGFR2. Mab 106blocks the binding of human VEGF with human VEGFR2 but not the bindingof murine VEGF with murine VEGFR2.

FIG. 8A depicts the binding of Mab106 and Mab 147 to human VEGFR2 onHUVEC (Human Umbilical Vein Endothelial Cells) and porcine aorticendothelial (PAE) cells overexpressing KDR (KDR-PAE). FIG. 8B show Mab147, but not Mab 106, binds to VEGFR2 on MS1 murine endothelial cells.In FIGS. 8A and 8B, the control is an antibody that binds to hVEGFR2 butnot mVEGFR2.

FIG. 9 shows inhibition of VEGFR2-mediated signal transduction by Mab106 and Mab 147. Mab 106 and Mab 147 inhibit phosphorylation of KDR andp44/42 in KDR-PAE (FIG. 9A) cells and in HUVEC (FIG. 9B) in a dosedependent manner.

FIG. 10A depicts inhibition of proliferation of KDR-PAE cells by Mab106, Mab 147, and a control antibody that binds to hVEGFR2. FIG. 10Bshows inhibition of induced cell migration. Migration of KDR-PAE cellswas induced with a VEGF gradient (50 ng/ml VEGF (up), 100 ng/ml VEGF(low)). The plot depicts cell counts in the presence of 0.6 μg/ml, 3μg/ml, or 15 μg/ml of Mab 106 or Mab 147 antibody.

FIG. 11 depicts inhibition of VEGF-induced migration of KDR-PAE cells byMab 147.

FIG. 12A depicts inhibition of VEGFR2-mediated signal transduction inmurine EOMA cells by Mab 147. And FIG. 12B depicts FACS studiesdemonstrating that Mab 147 has increased binding to EOMA cells bycomparison to control antibodies.

DETAILED DESCRIPTION

In one aspect, the invention provides novel VEGFR2 antibodies or antigenbinding fragments of such antibodies are employed, which are effectiveto inhibit VEGFR2-dependent signal transduction. As used herein,“inhibiting a receptor” means diminishing and/or inactivating theintrinsic kinase activity of the receptor to transduce a signal. Areliable assay for VEGFR2 inhibition is reduction of receptorphosphorylation.

The present invention is not limited by any particular mechanism ofVEGFR2 inhibition. The mechanism followed by one antibody is notnecessarily the same as that followed by another. Some possiblemechanisms include preventing binding of the VEGF ligand to theextracellular binding domain of the VEGFR2, and preventing dimerizationor oligomerization of receptors. Other mechanisms cannot, however, beruled out.

Antibodies are proteins that recognize and bind to a specific antigen orsubstance. In preferred embodiments, the antibodies of the presentinvention bind KDR at least as strongly as the natural ligand. Affinity,represented by the equilibrium constant for the dissociation of anantigen with an antibody (Kd), measures the binding strength between anantigenic determinant and an antibody binding site. Avidity is themeasure of the strength of binding between an antibody with its antigen.Avidity is related to both the affinity between an antigenic determinantand an antigen binding site on the antibody, and the number of bindingsites (valence) per antibody. For example, a monovalent antibody (e.g.,Fab) has one binding site for a particular epitope. An IgG antibody hastwo antigen binding sites. Typical values of K (the reciprocal of thedissociation constant K_(d)) are 10⁵ to 10¹¹ liters/mol. Any K weakerthan 10⁴ liters/mol is considered to indicate binding which isnonspecific.

Antibodies of the invention inhibit activation of VEGFR2. One measure ofVEGFR2 inhibition is reduced tyrosine kinase activity of the receptor.Tyrosine kinase inhibition can be determined using well-known methods,such as measuring the autophosphorylation level of the receptorInhibition of VEGFR2 can also be observed through inhibition orregulation of phosphorylation events of natural or synthetic VEGFR2substrates and other components of the VEGFR2 signal transductionpathway. Phosphorylation can be detected, for example, using an antibodyspecific for phosphotyrosine in an ELISA assay or on a western blot.Some assays for tyrosine kinase activity are described in Panek et al.,J. Pharmacol. Exp. Thera., 283: 1433-44 (1997) and Batley et al., LifeSci., 62: 143-50 (1998).

In vivo assays can also be utilized. For example, receptor tyrosinekinase inhibition can be observed by mitogenic assays using cell linesstimulated with receptor ligand in the presence and absence ofinhibitor. For example, HUVEC cells (ATCC) stimulated with VEGF can beused to assay VEGFR inhibition. Another method involves testing forinhibition of growth of VEGF-expressing tumor cells, using for example,human tumor cells injected into a mouse. See, U.S. Pat. No. 6,365,157(Rockwell et al.).

The invention provides anti-VEGFR2 antibodies, including nucleic acidsencoding such antibodies and compositions comprising such antibodies. Inone embodiment the invention provides an isolated antibody heavy chainvariable region comprising a CDR-1H, CDR-2H, and CDR-3H sequence,wherein:

(i) the CDR-1H sequence is GFTFSWYX₁MX₂, (SEQ ID NO: 185)wherein X₁ is V or I, X₂ is G or L, (ii) the CDR-2H sequence isSIX₁X₂SGGX₃TX₄YADSVKG, (SEQ ID NO: 186)wherein X₁ is Y or G, X₂ iS P or S, X₃ is A or F, X₄ is N or D, and(iii) the CDR-3H sequence is GNYFDY (SEQ ID NO: 3) or GLAAPRS.(SEQ ID NO: 11)

In one embodiment, the invention provides an isolated light chainvariable region comprising a CDR-L1, CDR-L2, and CDR-L3, wherein

(i) the CDR-L1 sequence is X₁GX₂X₃LX₄X₅X₆X₇X₈S, (SEQ ID NO: 187)wherein X₁ is S, Q, or T, X₂ is D, E, or Q, X₃ isK, S, N, I, or A, X₄ is G or R, X₅ is D, S, H, E,or N, X₆ is E, Y, Q, R, or N, X₇ is Y, F, or S, and X₈ is A or S, orSGSX₁SNX₂X₃X₄X₅X₆X₇X₈,  (SEQ ID NO: 188)wherein X₁ is S, or T, X₂ is I or L, X₃ is E or G,X₄ is T, S, or N, X₅ is N or Y, X₆ is T, P, A, orY, X₇ is V or L, and X₈ is N, I, or Y, or X₁GX₂SX₃DX₄GX₅YDYVS,(SEQ ID NO: 189) wherein X₁ is A or T, X₂ is S or T, X₃ is H, S, orN, X₄ is I or V, and X₅ is S or A, (ii) the CDR-L2 sequence isX₁X₂X₃X₄X₅PS, (SEQ ID NO: 190)wherein wherein X₁ is Q, D, T, Y, S, or A, X₂ isD, N, S, T, or V, X₃ is D, N, S, T, or Y, X₄ is Q,K, N, or L, and X₅ is R or L, and (iii) wherein the CDR-L3 sequence isQX₁WX₂X₃X₄X₅X₆X₇X₈, (SEQ ID NO: 191)wherein X₁ is A or T, X₂ is D or G, X₃ is R or noamino acid, X₄ is S, F, or N, X₅ is S, T, or N,X₆ is S, T, or P, X₇ is A, V, L, I, or Y, and X₈ is V or L, orAX₁WDDX₂LX₃X₄X₅X₆, (SEQ ID NO: 192wherein X₁ is A, S, or T, X₂ is N or S, X₃ is N,I, or G, X₄ is G or S, X₅ is P, W, or V, and X₆ is V or L, orMYSTITX₁LL, (SEQ ID NO: 193) wherein X₁ is A or T.

In one embodiment, the invention provides an isolated light chainvariable region comprising a CDR-L1, CDR-L2, and CDR-L3, wherein

(i) the CDR-L1 sequence is RASX₁X₂X₃X₄X₅X₆X₇YX₈X₉, (SEQ ID NO: 194)wherein X₁ is Q, E, or H, X₂ is S, R, or N, X₃ isV, I, or L, X₄ is S, R, G or N, X₅ is S or N, X₆is S, N, W, or D, X₇ is G or no amino acid, X₈ isL or F, and X₉ is A, G, M, or S, (ii) the CDR-L2 sequence is GASX₁RAT,(SEQ ID NO: 195) wherein X₁ is S, T, I, or N, and(iii) the CDR-L3 sequence is QQX₁X₂X₃X₄X₅X₆X₇X₈, (SEQ ID NO: 196)wherein X₁ is F or Y, X₂ is D, G, or Y, X₃ is S,T, or N, X₄ is S, L, or W, X₅ is P or no aminoacid, X₆ is P or T, X₇ is L, I, V, P, W, or Y, and X₈ is T or S.

In an embodiment of the invention, an antibody is provided whichcomprises a heavy chain variable domain comprising one, two, three,four, five, or six of the light chain variable domain and heavy chainvariable domain CDR sequences set forth above.

Non-limiting examples of VEGFR2-binding antibody sequences are provided.As described herein, from human Fab phage display libraries, twoneutralizing antibodies were identified that bind to human VEGFR2, blockbinding of the ligand VEGFA to hVEGFR2, and inhibit the VEGFR2phosphorylation and downstream signal transduction stimulated by VEGFA.Table 1 indicates amino acid sequences of the CDRs and variable domainsof antibodies of the antibodies. The K_(d)s of Mab 101 and Mab 102 areabout 6.6 mM and 1.7 nM, respectively.

TABLE 1 Antibody Amino Acid Sequences by SEQ ID NO CDR- CDR- CDR- V_(H)CDR- CDR- CDR- V_(L) Mab H1 H2 H3 domain L1 L2 L3 domain 101 1 2 3 4 5 67 8 102 9 10 11 12 13 14 15 16

The heavy chain of Mab 101 was reshuffled with κ light chain genes(κ-library) and λ light chain genes (λ-library). 20 unique λ light chainvariants were found by panning the λ-library against both human VEGFR2and mouse VEGFR2. 22 unique κ light chain variants were found by panningthe λ-library against both human VEGFR2 and mouse VEGFR2. Table 2indicates amino acid sequences of the CDRs and variable domains of thelight chains. The K_(d)s of Mabs 105, 106, and 107 were increased about10 fold (0.24 nM, 0.22 nM, and 0.12 nM, respectively). Like the parentantibody, these antibodies bind to VEGFR2 and block binding of VEGFA toVEGFR2, and inhibit VEGFA-stimulated phosphorylation of VEGFR2, AKT, andMAPK. (FIG. 4).

Several of the antibodies, including Mabs 138, 139, 140, and 146, alsocross react with mouse VEGFR2. These antibodies also inhibitedVEGFA-stimulated phosphorylation of VEFGR2 and downstream signaltransduction molecules, including MAPK.

TABLE 2 κ and λ light chains by SEQ ID NO SEQ ID NO light CDR- CDR- CDR-Mab chain L1 L2 L3 V_(L) 103 λ 17 18 19 20 104 λ 21 22 23 24 105 λ 25 2627 28 106 λ 29 30 31 32 107 λ 33 34 35 36 108 λ 37 38 39 40 109 λ 41 4243 44 110 λ 45 46 47 48 111 λ 49 50 51 52 112 λ 53 54 55 56 113 λ 57 5859 60 114 λ 61 62 63 64 115 λ 65 66 67 68 116 λ 69 70 71 72 117 λ 73 7475 76 118 λ 77 78 79 80 119 λ 81 82 83 84 120 λ 85 86 87 88 121 λ 89 9091 92 122 λ 93 94 95 96 123 κ 97 98 99 100 124 κ 101 102 103 104 125 κ105 106 107 108 126 κ 109 110 111 112 127 κ 113 114 115 116 128 κ 117118 119 120 129 κ 121 122 123 124 130 κ 125 126 127 128 131 κ 129 130131 132 132 κ 133 134 135 136 133 κ 137 138 139 140 134 κ 141 142 143144 135 κ 145 146 147 148 136 κ 149 150 151 152 137 κ 153 154 155 156138 κ 157 158 159 160 139 κ 161 162 163 164 140 κ 165 166 167 168 141 κ169 170 171 172 142 κ 173 174 175 176 143 κ 177 178 179 180 144 κ 181182 183 184

The invention provides an isolated VEGFR2 antibody, and VEGFR2 bindingfragments thereof, which comprises one, two, or three heavy chain CDRsand one, two, or three light chain CDRs, selected from the sequences setforth in Table 1 and Table 2. In an antibody of the invention, when morethan one CDR is selected from the sequences presented in Table 1 andTable 2, the different CDRs need not be selected from the samemonoclonal antibody presented in those tables, but can be selected fromtwo or more antibody variable domains presented in the tables. Specificembodiments include, but are not limited to, the following. In anembodiment of the invention, the isolated VEGFR2 antibody comprises one,two, or three heavy chain CDRs having SEQ ID NO:1, SEQ ID NO:2, and SEQID NO:3. In an embodiment, of the invention, the antibody comprises one,two, or three light chain CDRs having SEQ ID NO:5, SEQ ID NO:6, and SEQID NO:7. In another embodiment, the antibody comprises one, two, orthree light chain CDRs having sequences as set forth in Table 1 or 2.Non-limiting examples include a light chain variable region comprisingone or more of SEQ ID NO:25, SEQ ID NO:26, and SEQ ID NO:27, one or moreof SEQ ID NO:29, SEQ ID NO:30, and SEQ ID NO:31, or one or more of SEQID NO:33, SEQ ID NO:34, and SEQ ID NO:35. In certain embodiments, theVEGFR2 antibody comprises a heavy chain variable domain comprising SEQID NO:4 or SEQ ID NO:12. In certain embodiments, the VEGFR2 antibodycomprises a light chain variable domain comprising SEQ ID NO:8, SEQ IDNO:16, SEQ ID NO:27, SEQ ID NO:31, or SEQ ID NO:35. In certainembodiments, the antibodies comprise one of the above-mentioned heavychain variable domains and one of the above-mentioned light chainvariable domains. In certain embodiments, the VEGFR2 antibodies orbinding fragments thereof comprise one or more CDRs or one or morevariable domains with an amino acid sequence at least 85% at least 90%,at least 95%, at least 97%, at least 98%, or at least 99%, identical tothe CDR and variable domain sequences set forth in Table 1 or 2. Incertain embodiments, antibodies of the invention have CDR amino acidsidentical to those disclosed herein and frameworks that are at leastleast 85%, at least 90%, of at least 95% identical.

“Identity” refers to the number or percentage of identical positionsshared by two amino acid or nucleic acid sequences, taking into accountthe number of gaps, and the length of each gap, which need to beintroduced for optimal alignment of the two sequences. “Substantiallyidentical” means an amino acid sequence that which differs only byconservative amino acid substitutions, for example, substitution of oneamino acid for another of the same class (e.g., valine for glycine,arginine for lysine, etc.) or by one or more non-conservativesubstitutions, deletions, or insertions located at positions of theamino acid sequence which do not destroy the function of the protein.Preferably, the amino acid sequence is at least 80%, more preferably atleast 85%, and most preferably at least 90% similar to another aminoacid sequence. Methods and computer programs for determining sequencesimilarity are publically available, including, but not limited to, theGCG program package (Devereux et al., Nucleic Acids Research 12: 387,1984), BLASTP, BLASTN, FASTA (Altschul et al., J. Mol. Biol. 215:403(1990), and the ALIGN program (version 2.0). The well-known SmithWaterman algorithm may also be used to determine similarity. The BLASTprogram is publicly available from NCBI and other sources (BLAST Manual,Altschul, et al., NCBI NLM NIH, Bethesda, Md. 20894; BLAST 2.0). Incomparing sequences, these methods account for various substitutions,deletions, and other modifications. Conservative substitutions typicallyinclude substitutions within the following groups: glycine, alanine;valine, isoleucine, leucine; aspartic acid, glutamic acid, asparagine,glutamine; serine, threonine; lysine, arginine; and phenylalanine,tyrosine.

Antibodies of the invention also include those for which bindingcharacteristics have been improved by direct mutation, methods ofaffinity maturation, phage display, or chain shuffling. Affinity andspecificity may be modified or improved by mutating CDRs and screeningfor antigen binding sites having the desired characteristics. CDRs aremutated in a variety of ways. One way is to randomize individualresidues or combinations of residues so that in a population ofotherwise identical antigen binding sites, all twenty amino acids arefound at particular positions. Alternatively, mutations are induced overa range of CDR residues by error prone PCR methods (see, e.g., Hawkinset al., J. Mol. Biol., 226: 889-896 (1992)). For example, phage displayvectors containing heavy and light chain variable region genes may bepropagated in mutator strains of E. coli (see, e.g., Low et al., J. Mol.Biol., 250: 359-368 (1996)). These methods of mutagenesis areillustrative of the many methods known to one of skill in the art.

To minimize the immunogenicity of antibodies that bind to VEGFreceptors, the present invention provides antibodies which comprisehuman variable and constant domain sequences. The antibodies may be ormay combine members of any immunoglobulin class, such as IgG, IgM, IgA,IgD, or IgE, and the subclasses thereof. The antibody class may beselected to optimize effector functions (e.g., complement dependentcytoxicity (CDC) and antibody dependent cellular cytoxicity (ADCC)) ofnatural antibodies.

Certain embodiments of the invention involve the use of VEGFR2-bindingantibody fragments. An Fv is the smallest fragment that contains acomplete heavy and light chain variable domain, including all sixhypervariable loops (CDRs). Lacking constant domains, the variabledomains are noncovalently associated. The heavy and light chains may beconnected into a single polypeptide chain (a “single-chain Fv” or“scFv”) using a linker that allows the V_(H) and V_(L) domains toassociate to form an antigen binding site. In an embodiment of theinvention, the linker is (Gly-Gly-Gly-Gly-Ser)₃. Since scFv fragmentslack the constant domains of whole antibodies, they are considerablysmaller than whole antibodies. scFv fragments are also free of normalheavy-chain constant domain interactions with other biological moleculeswhich may be undesired in certain embodiments.

Fragments of an antibody containing V_(H), V_(L), and optionally C_(L),C_(H)1, or other constant domains can also be used. Monovalent fragmentsof antibodies generated by papain digestion are referred to as Fab andlack the heavy chain hinge region. Fragments generated by pepsindigestion, referred to as F(ab′)₂, retain the heavy chain hinge and aredivalent. Such fragments may also be recombinantly produced. Many otheruseful antigen-binding antibody fragments are known in the art, andinclude, without limitation, diabodies, triabodies, single domainantibodies, and other monovalent and multivalent forms.

The invention further provides multivalent antigen-binding proteins,which can be in the form, without limitation, of antibodies,antigen-binding fragments thereof, and proteins comprising all or partof antigen-binding portions of antibodies. Multivalent antigen-bindingproteins may be monospecific, bispecific, or multispecific. The termspecificity refers to the number of different types of antigenicdeterminants to which a particular molecule can bind. If animmunoglobulin molecule binds to only one type of antigenic determinant,the immunoglobulin molecule is monospecific. If the immunoglobulinmolecule binds to different types of antigenic determinants then theinimunoglobulin molecule is multispecific.

For example, a bispecific multivalent single chain antibody allows forthe recognition of two different types of epitopes. Both epitopes may beon the same antigen (e.g., VEGFR2). Alternatively, one epitope may be onone antigen (e.g., VEGFR2), and the second epitope on a differentantigen.

In one embodiment, a multivalent single chain antibody includes avariable light-chain fragment linked to a variable heavy-chain fragment(similar to an scFv), which is further linked by another peptide linkerto at least one other antigen binding domain. Typically, the peptidelinker is composed of about fifteen amino acid residues. In a preferredembodiment, the number of V_(L) and V_(H) domains is equivalent. Forexample, a bivalent single chain antibody can be represented as follows:V_(L)-L₁-V_(H)-L₂-V_(L)-L₃-V_(H) or V_(L)-L₁-V_(H)-L₂-V_(H)-L₃-V_(L) orV_(H)-L₁-V_(L)-L₂-V_(H)-L₃-V_(L) or V_(H)-L₁-V_(L)-L₂-VL-L₃-V_(H).Multivalent single chain antibodies which are trivalent or greater haveone or more antibody fragments joined to a bivalent single chainantibody by additional peptide linkers. One example of a trivalentsingle chain antibody is:V_(L)-L₁-V_(H)-L₂-V_(L)-L₁-V_(H)-L₂-V_(L)-L₁-V_(H).

Two single chain antibodies can be combined to form a diabody, alsoknown as bivalent dimer. Diabodies have two chains. Each chain of thediabody includes a V_(H) domain connected to a V_(L) domain by a shortlinker of about 5-10 amino acid residues, e.g. (Gly-Gly-Gly-Gly-Ser),SEQ ID NO:251; (Gly-Gly-Gly-Gly-Ser)₂, SEQ ID NO:252. Such linkers areshort enough to prevent intrachain pairing between domains on the samechain, thus driving interchain pairing between complementary domains ondifferent chains and recreate two antigen-binding sites. The diabodystructure is rigid and compact, with antigen-binding sites are atopposite ends of the molecule. Diabodies may be monospecific orbispecific.

Three single chain antibodies can be combined to form a triabody, alsoknown as a trivalent trimers. In some embodiments, triabodies areconstructed with the carboxy terminus of a V_(L) or V_(H) domaindirectly fused to the amino terminus of a V_(H) or V_(L) domain, i.e.,without any linker sequence. The triabody has three Fv heads with thepolypeptides arranged in a cyclic, head-to-tail fashion. A possibleconformation of the triabody molecule is planar with the three bindingsites located in a plane at an angle of 120 degrees from one another.Triabodies may be monospecific, bispecific or trispecific.

It is understood that the anti-VEGFR2 antibodies of the invention, whereused in a mammal for the purpose of prophylaxis or treatment, will beadministered in the form of a composition additionally comprising apharmaceutically acceptable carrier. Suitable pharmaceuticallyacceptable carriers include, for example, one or more of water, saline,phosphate buffered saline, dextrose, glycerol, ethanol and the like, aswell as combinations thereof. Pharmaceutically acceptable carriers mayfurther comprise minor amounts of auxiliary substances such as wettingor emulsifying agents, preservatives or buffers, which enhance the shelflife or effectiveness of the antibodies.

In the methods of the present invention, a therapeutically effectiveamount of an antibody of the invention is administered to a mammal inneed thereof. The term “administering” as used herein means deliveringthe antibodies of the present invention to a mammal by any method thatmay achieve the result sought. They may be administered, for example,intravenously or intramuscularly. Although human antibodies of theinvention are particularly useful for administration to humans, they maybe administered to other mammals as well. The term “mammal” as usedherein is intended to include, but is not limited to, humans, laboratoryanimals, domestic pets and farm animals. “Therapeutically effectiveamount” means an amount of antibody of the present invention that, whenadministered to a mammal, is effective in producing the desiredtherapeutic effect, such as inhibiting kinase activity. For example,depending on the disease, for an antibody, this may require 0.1, 1.0,3.0, 6.0, or 10.0 mg/Kg. For an IgG having a molecular mass of 150,000g/mole (two binding sites), these doses correspond to approximately 18nM, 180 nM, 540 nM, 1.08 μM, and 1.8 μM of binding sites for a 5 L bloodvolume.

Antibodies of the invention are useful for inhibiting tumor growth,angiogenesis associated with tumor growth, or other pathologic conditionassociated with angiogenesis. Tumors that can be treated include primarytumors, metastatic tumors, and refractory tumors. Refractory tumorsinclude tumors that fail to respond or are resistant to treatment withchemotherapeutic agents alone, antibodies alone, radiation alone orcombinations thereof. Refractory tumors also encompass tumors thatappear to be inhibited by treatment with such agents, but recur up tofive years, sometimes up to ten years or longer after treatment isdiscontinued. The antibodies are effective for treating vascularizedtumors and tumor that are not vascularized, or not yet substantiallyvascularized.

Examples of solid tumors which may be accordingly treated include breastcarcinoma, lung carcinoma, colorectal carcinoma, pancreatic carcinoma,glioma and lymphoma. Some examples of such tumors include epidermoidtumors, squamous tumors, such as head and neck tumors, colorectaltumors, prostate tumors, breast tumors, lung tumors, including smallcell and non-small cell lung tumors, pancreatic tumors, thyroid tumors,ovarian tumors, and liver tumors. Other examples include Kaposi'ssarcoma, CNS neoplasms, neuroblastomas, capillary hemangioblastomas,meningiomas and cerebral metastases, melanoma, gastrointestinal andrenal carcinomas and sarcomas, rhabdomyosarcoma, glioblastoma,preferably glioblastoma multiforme, and leiomyosarcoma. Examples ofvascularized skin cancers for which the antagonists of this inventionare effective include squamous cell carcinoma, basal cell carcinoma andskin cancers that can be treated by suppressing the growth of malignantkeratinocytes, such as human malignant keratinocytes.

Examples of non-solid tumors include leukemia, multiple myeloma andlymphoma. Some examples of leukemias include acute myelogenous leukemia(AML), chronic myelogenous leukemia (CML), acute lymphocytic leukemia(ALL), chronic lymphocytic leukemia (CLL), erythrocytic leukemia ormonocytic leukemia. Some examples of lymphomas include Hodgkin's andnon-Hodgkin's lymphoma.

Antibodies of the invention can also be used to treat or preventingpathologic conditions characterized by excessive angiogenesis,involving, for example, vascularization and/or inflammation, such asatherosclerosis, rheumatoid arthritis (RA), hemangiomas, angiofibromas,and psoriasis. Other non-limiting examples of non-neoplastic angiogenicdisease are retinopathy of prematurity (retrolental fibroplastic),corneal graft rejection, insulin-dependent diabetes mellitus, multiplesclerosis, myasthenia gravis, Chron's disease, autoimmune nephritis,primary biliary cirrhosis, acute pancreatitis, allograph rejection,allergic inflammation, contact dermatitis and delayed hypersensitivityreactions, inflammatory bowel disease, septic shock, osteoporosis,osteoarthritis, cognition defects induced by neuronal inflammation,Osler-Weber syndrome, restinosis, and fungal, parasitic and viralinfections, including cytomegaloviral infections.

Ocular diseases characterized by excessive angiogeneis includeneovascular glaucoma, proliferative retinopathy including proliferativediabetic retinopathy, and macular degeneration The invention providesmethods and compounds for treating ocular diseases and disorders. In oneembodiment, the invention provides for treating age related maculardegeneration (AMD), which occurs in “dry” and “wet” forms. The “wet”form of AMD causes vision loss due to abnormal blood vessel growth(neovascularization). Bleeding, leaking, and scarring from these retinalblood vessels eventually causes irreversible damage to thephotoreceptors. The dry form results from atrophy of the retinal pigmentepithelial layer, which causes vision loss through loss ofphotoreceptors (rods and cones) in the central part of the eye. Inanother embodiment, the invention provides a method of treatingchoroidal neovascularization (CNV). Choroidal neovascularization is aprocess in which new blood vessels grow in the choroid, through theBruch membrane and invade the subretinal space, and is a symptom of,among other causes, age-related macular degeneration, myopia and oculartrauma. In another embodiment, the invention provides a method oftreating diabetic macular edema (DME). In another embodiment, theinvention provides a method of treating macular edema that is secondaryto branch retinal vein occlusion (BRVO) or central retinal veinocclusion (CRVO). Other diseases treatable according to the inventioninclude, without limitation, iris neovascularization, uveitis,neovascular glaucoma, and retinitis of prematurity (ROP). The method oftreatment can be prophylactic, such as to stave off cornealneovascularization after corneal transplant, or to modulate the wounndhealing process in trabeculectomy surgery.

Antibodies and antigen binding fragments of the invention can beadvantageously administered with second agents to patients in needthereof. For example, in some embodiments, a VEGFR-2 antibody of theinvention is administered to a subject with an anti-neoplastic agent. Insome embodiments, a VEGFR-2 antibody is administered to a subject with asecond angiogenesis inhibitor. In some embodiments, a VEGFR-2 antibodyof the invention is administered with an anti-inflammatory agent or animmunosuppressant.

Antineoplastic agents include cytotoxic chemotherapeutic agents,targeted small molecules and biological molecules, and radiation.Non-limiting examples of chemotherapeutic agents include cisplatin,dacarbazine (DTIC), dactinomycin, irinotecan, mechlorethamine (nitrogenmustard), streptozocin, cyclophosphamide, carmustine (BCNU), lomustine(CCNU), doxorubicin (adriamycin), daunorubicin, procarbazine, mitomycin,cytarabine, etoposide, methotrexate, 5-fluorouracil, vinblastine,vincristine, bleomycin, paclitaxel (taxol), docetaxel (taxotere),aldesleukin, asparaginase, busulfan, carboplatin, cladribine,dacarbazine, floxuridine, fludarabine, hydroxyurea, ifosfamide,interferon alpha, leuprolide, megestrol, melphalan, mercaptopurine,plicamycin, mitotane, pegaspargase, pentostatin, pipobroman, plicamycin,streptozocin, tamoxifen, teniposide, testolactone, thioguanine,thiotepa, uracil mustard, vinorelbine, chlorambucil, taxol andcombinations thereof.

Targeted small molecules and biological molecules include, withoutlimitation, inhibitors of components of signal transduction pathways,such as modulators of tyrosine kinases and inhibitors of receptortyrosine kinases, and agents that bind to tumor-specific antigens.Non-limiting examples of growth factor receptors involved intumorigenesis are the receptors for platelet-derived growth factor(PDGFR), insulin-like growth factor (IGFR), nerve growth factor (NGFR),and fibroblast growth factor (FGFR), and receptors of the epidermalgrowth factor receptor family, including EGFR (erbB1), HER2 (erbB2),erbB3, and erbB4.

EGFR antagonists induce antibodies that bind to EGFR or to an EGFRligand, and inhibits ligand binding and/or receptor activation. Forexample, the agent can block formation of receptor dimers or heterodimerwith other EGFR family members. Ligands for EGFR include, for example,EGF, TGF-α amphiregulin, heparin-binding EGF (HB-EGF) andbetarecullulin. An EGFR antagonist can bind externally to theextracellular portion of EGFR, which may or may not inhibit binding ofthe ligand, or internally to the tyrosine kinase domain. EGFRantagonists further include agents that inhibit EGFR-dependent signaltransduction, for example, by inhibiting the function of a component ofthe EGFR signal transduction pathway. Examples of EGFR antagonists thatbind EGFR include, without limitation, biological molecules, such asantibodies (and functional equivalents thereof) specific for EGFR, andsmall molecules, such as synthetic kinase inhibitors that act directlyon the cytoplasmic domain of EGFR.

Small molecule and biological inhibitors include inhibitors of epidermalgrowth factor receptor (EGFR), including gefitinib, erlotinib, andcetuximab, inhibitors of HER2 (e.g., trastuzumab, trastuzumab emtansine(trastuzumab-DM1; T-DM1) and pertuzumab), anti-VEGF antibodies andfragments (e.g., bevacizumab), antibodies that inhibit CD20 (e.g.,rituximab, ibritumomab), anti-VEGFR antibodies (e.g., ramucirumab(IMC-1121B), IMC-1C11, and CDP791), anti-PDGFR antibodies, and imatinib.Small molecule kinase inhibitors can be specific for a particulartyrosine kinase or be inhibitors of two or more kinases. For example,the compoundN-(3,4-dichloro-2-fluorophenyl)-7-({[(3aR,6aS)-2-methyloctahydrocyclopenta[c]pyrrol-5-yl]methyl}oxy)-6-(methyloxy)quinazolin-4-amine (also known asXL647, EXEL-7647 and KD-019) is an in vitro inhibitor of severalreceptor tyrosine kinases (RTKs), including EGFR, EphB4, KDR (VEGFR),Flt4 (VEGFR3) and ErbB2, and is also an inhibitor of the SRC kinase,which is involved in pathways that result in nonresponsiveness of tumorsto certain TKIs. In an embodiment of the invention, treatment of asubject in need comprises administration of a rho-kinase inhibitor ofFormula I and administration of KD-019.

Dasatinib (BMS-354825; Bristol-Myers Squibb, New York) is another orallybioavailable, ATP-site competitive Src inhibitor. Dasatanib also targetsBcr-Abl (FDA-approved for use in patients with chronic myelogenousleukemia (CML) or Philadelphia chromosome positive (Ph+) acutelymphoblastic leukemia (ALL)) as well as c-Kit, PDGFR, c-FMS, EphA2, andSFKs. Two other oral tyrosine kinase inhibitor of Src and Bcr-Abl arebosutinib (SKI-606) and saracatinib (AZD0530).

While VEGFR2 mediates the majority of the downstream effects of VEGF inangiogenesis, it can be advantageous to administer a second angiogenesisinhibitor. Anti-VEGFR-2 antibodies of the invention may be administeredwith antibodies that neutralize other receptors involved in tumor growthor angiogenesis.

Non-limiting examples of VEGF-binding agents include VEGF antibodies andVEGF traps (i.e., ligand binding domains of VEGF receptors. Two examplesof antibodies (including VEGF-binding antibody fragments) arebevacizumab (Avastin), an antibody which binds to VEGF-A, andranibizumab (Lucentis), an Fab derived from bevacizumab. In general, aVEGF trap is a protein that comprises VEGF binding domains of one ormore VEGF receptor protein. VEGF-traps include, without limitation,soluble VEGFR-1, soluble neuropilin 1 (NRP1), soluble VEGFR-3 (whichbinds VEGF-C and VEGF-D), and aflibercept (Zaltrap; Eylea; VEGF TrapR1R2), comprised of segments of the extracellular domains of humanvascular endothelial growth factor receptors VEGFR1 and VEGFR2 fused tothe constant region (Fc) of human IgG1. Conbercept (KH902) is a fusionprotein which contains the extracellular domain 2 of VEGFR-1 (Flt-1) andextracellular domain 3, 4 of VEGFR-2 (KDR) fused to the Fc portion ofhuman IgG1. Several VEGF traps containing KDR and FLT-1 Ig-like domainsin various combinations are disclosed in U.S. Pat. No. 8,216,575.DARPins (an acronym for designed ankyrin repeat proteins) aregenetically engineered antibody mimetic proteins typically exhibitinghighly specific and high-affinity target protein binding. DARPin® MP0112is a vascular endothelial growth factor (VEGF) inhibitor and has enteredclinical trials for the treatment of wet macular degeneration anddiabetic macular edema.

According to the invention, VEGF expression can be targeted. Forexample, VEGF inhibitor PTC299 targets VEGF post-transcriptionally byselectively binding the 5′- and 3′-untranslated regions (UTR) of VEGFmessenger RNA (mRNA), thereby preventing translation of VEGF. Pegaptanib(Macugen) is an RNA aptamer directed against VEGF-165.

Placental growth factor (PlGF) has been implicated in pathologicalangiogenesis. PlGF is structurally related to VEGF and is also a ligandfor VEGFR-1. Consequently, VEGF traps comprising the extracellulardomain of VEGFR1 (see above) are useful for targeting PlGF.Anti-angiogenic agents further include those that bind to theVEGFR-1/Flt-1 receptor. In certain embodiments, the antigen-bindingproteins that bind to the extracellular domain of VEGFR-1 block bindingby one or both of its ligands, VEGF and PlGF, and/or neutralizeVEGF-induced or PlGF-induced activation of VEGFR-1.

PDGF is composed of four polypeptide chains that form homodimersPDGF-AA, BB, CC, and DD as well as the heterodimer PDGF-AB. The PDGFreceptors (PDGFR)-α and -β mediate PDGF functions. Specifically, PDGFRαbinds to PDGF-AA, -BB, -AB, and -CC, whereas PDGFRβ interacts with -BBand -DD. Non-limiting examples of PDGF-binding agents include anti-PDGFantibodies and PDGF traps. Agents that target PDGF include Fovista™(E10030, Ophthotech), a pegylated aptamer targeting PDGF-B, and AX102(Sennino et al., 2007, Cancer Res. 75(15):7359-67), a DNAoligonucleotide aptamer that binds PDGF-B.

In certain embodiments of the present invention, an antibody or anantigen binding fragment thereof is administered to a subject togetherwith an effective amount of a PDGFRβ antibody

Agents that target PDGF receptors include ramucirumab (IMC-3G3, humanIgG₁) an anti-PDGFRα antibody, crenolanib (CP-868596), a selectiveinihibitor of PDGFRα (IC₅₀=0.9 nM) and PDGFRβ (IC₅₀=1.8 nM), andnilotinib (Tasigna®), an inhibitor of PDGFRα and PDGFRβ and othertyrosine kinases.

Angiogenesis inhibitors include intracellular agents that block signaltransduction mediated by, for example, VEGF, PDGF, ligands of VEGF orPDGF receptors, or complement. Intracellular agents that inhibitangiogenesis inhibitors include the following, without limitation.Sunitinib (Sutent; SU11248) is a panspecific small-molecule inhibitor ofVEGFR1-VEGFR3, PDGFRα and PDGFRβ, stem cell factor receptor (cKIT),Flt-3, and colony-stimulating factor-1 receptor (CSF-1R). Axitinib(AG013736; Inlyta) is another small molecule tyrosine kinase inhibitorthat inhibits VEGFR-1-VEGFR-3, PDGFR, and cKIT. Cediranib (AZD2171) isan inhibitor of VEGFR-1-VEGFR-3, PDGFRβ, and cKIT. Sorafenib (Nexavar)is another small molecular inhibitor of several tyrosine proteinkinases, including VEGFR, PDGFR, and Raf kinases. Pazopanib (Votrient;(GW786034) inhibits VEGFR-1, -2 and -3, cKIT and PDGFR. Foretinib(GSK1363089; XL880) inhibits VEGFR2 and MET, as does cabozantinib(Cometriq; XL184). Ponatinib (Iclusig; AP24534) inhibits VEGFR, PDGFRand c kit. Tivozanib (AV-951) inhibits VEGFR-1, VEGFR-2 and VEGFR-3 atpicomolar concentrations. CP-547632 is as a potent inhibitor of theVEGFR-2 and basic fibroblast growth factor (FGF) kinases. E-3810((6-(7-((1-aminocyclopropyl)methoxy)-6-methoxyquinolin-4-yloxy)-N-methyl-1-naphthamide) inhibitsVEGFR-1, -2, and -3 and FGFR-1 and -2 kinases in the nanomolar range.Brivanib (BMS-582664) is a VEGFR-2 inhibitor that also inhibits FGFreceptor signaling. CT-322 (Adnectin) is a small protein based on ahuman fibronectin domain and binds to and inhibits activation of VEGFR2.Vandetanib (Caprelas; Zactima; ZD6474) is an inhibitor of VEGFR2, EGFR,and RET tyrosine kinases. X-82 (Xcovery) is a small molecule indolinoneinhibitor of signaling through the growth factor receptors VEGFR andPDGFR.

In certain embodiments, anti-VEGFR antibodies of the invention arecoadministered with matrix metalloproteinase inhibitors. Matrixmetalloproteases (MMPs), such as MMP-14, MMP-16, and MMP-24, cleavecomponents of the extracellular matrix (ECM) and basement membranes,thereby allowing cancer cells to penetrate and infiltrate the subjacentstromal matrix. Additionally, a number of growth-factor receptors, celladhesion molecules, chemokines, cytokines, apoptotic ligands, andangiogenic factors are substrates of MMPs. Hence, MMP activity may causeactivation of growth factors, suppression of tumor cell apoptosis,destruction of chemokine gradients developed by host immune response, orrelease of angiogenic factors. MMPs may facilitate tumor growth bypromoting the release of cell proliferation factors such as insulin-likegrowth factors which are bound to specific binding proteins (IGFBPs)(Manes et al., 1997 J. Biol. Chem. 272: 25706-25712).

Collagenases, including MMP-2, have been found at elevated levels inmelanoma and in cancers of the colon, breast, lung, prostate, andbladder. Usually, these elevated levels correlate with higher tumorgrade and invasiveness. MMP-2 levels are significantly elevated in theserum of patients with metastatic lung cancer, and in those patientswith high levels, response to chemotherapy is diminished. MMP-14, whichcleaves proMMP-2 to release active MMP-2, is elevated in numerouscancers and can contribute to the growth of tumors, tumor embolism, andthe mobility, invasiveness and metastasis of cancer (e.g., CNS tumors(e.g., gliomas), head and neck cancer, oral cavity cancer, laryngealcancer, chondrosarcoma, breast cancer). MMP-16 and MMP-24 are alsoelevated in numerous cancers and can contribute to both the growth oftumors and the invasiveness and metastasis of cancer (e.g., breastcancer, laryngeal cancer, ovarian cancer, testicular carcinoma,melanoma, brain tumors (e.g., astrocytomas, glioblastomas, gliomas).

In certain embodiments, anti-VEGFR antibodies of the invention arecoadministered with MMP-14 antagonists, including but not limited toanti-MMP-14 antibodies disclosed in U.S. Pat. Nos. 7,745,587 and8,106,168. In one embodiment, the antibody is human monoclonal antibodyDX-2400 (Dyax Corp). Coadministration with such an antibody is suitablefor treatment of human carcinomas, including but not limited to, uterinecervix, stomach, lung, breast, colon, head and neck, malignant braintumors, and melanoma.

In another embodiment, a VEGFR2 antibody of the invention can beadministered in combination with one or more suitable adjuvants, suchas, for example, cytokines (IL-10 and IL-13, for example) or otherimmune stimulators. It should be appreciated, however, thatadministration of only an anti-KDR antibody is sufficient to prevent,inhibit, or reduce the progression of the tumor in a therapeuticallyeffective manner.

Anti-inflammatories and immunosuppressants include steroid drugs such asglucocorticoids (e.g., dexamethasone), FK506 (tacrolimus), ciclosporin,fingolimod, interferon, such as IFNβ or IFNγ, a tumor necrosisfactor-alpha (TNF-α) binding protein such as infliximab (Remicade),etanercept (Enbrel), or adalimumab (Humira), and mycophenolic acid.

Certain embodiments comprise administering an antibody of the inventionand a second agent as follows: docetaxel for solid tumors, includingbreast cancer and urinary tract and renal cancers, paclitaxel (solidtumors, gastric adenocarcinoma), FOLFRI (i.e, irinotican, folinic acid,5-Florouracil) for colorectal cancer, capecitabine (breast cancer),FOLFOX (i.e., oxaliplatin, leucovorin, 5-Fluorouracil) (gastric,esophageal, gastroesophageal cancers), eribulin (breast cancer), FOLFIRI(i.e., irinotecan, levofolinate, 5-Fluorouracil) (colorectal carcinoma),carboplatin (NSCLC), mitoxantrone and prednisone (prostate cancer), OFF(oxaliplatin folinic acid, 5-Florouracil) (colorectal cancer),irinotican and cetuximab (colorectal cancer), and dacarbazine (malignantmelanona).

The antibodies and antigen binding fragments of the invention can beconjugated to an agent, e.g., a cytotoxic drug, cytotoxin enzyme, orradioisotope. This method includes administering the binding proteinalone or attached to an agent (e.g., a cytotoxic drug), to a subjectrequiring such treatment. For example, VEGFR2 antibodies or fragmentsthereof may be used to deliver nanoparticles containing agents, such astoxins, to VEGFR2 associated cells or tissues, e.g., tumors.

The VEGFR2 binding proteins can be used directly in vivo to eliminateantigen-expressing cells via natural complement-dependent cytotoxicity(CDC) or antibody dependent cellular cytotoxicity (ADCC). The bindingproteins described herein can include complement binding effectordomain, such as the Fc portions from IgG1, -2, or -3 or correspondingportions of IgM which bind complement.

When a VEGFR-2 antibody of the invention is administered with a secondagent, the first and second agents can be adminstered sequentially orsimultaneously. Each agent can be administered in single or multipledoses, and the doses can be administered on any schedule, including,without limitation, twice daily, daily, weekly, every two weeks, andmonthly.

The invention also includes adjunctive administration. Adjunctiveadministration means that a second agent is administered to a patient inaddition to a first agent that is already being administered to treat adisease or disease symptom. In some embodiments, adjunctiveadministration includes administering a second agent to a patient inwhich administration of the first agent did not treat, or did notsufficiently treat, the disease or disease symptom. In otherembodiments, adjunctive administration includes administration of thesecond agent to a patient whose disease has been effectively treated byadministration of the first agent.

In one embodiment of the invention, an antibody or an antigen bindingfragment thereof is administered by injection, a small moleculeadministered orally. In one such embodiment, the antibody isadministered weekly or once or twice per month and the small molecule isadministered daily.

In an embodiment of the invention, an antibody or an antigen bindingfragment thereof is administered by injection, and a ROCK2 inhibitor isadministered orally. In a preferred embodiment, the agents areadministered once daily. According to the invention, when a ROCKinhibitor, or a VEGFR2 antibody are administered to a subject to treatan ocular disease, a TGF-β antagonist can be administered to the subjectto reduce or prevent scarring. For example, in an embodiment of theinvention, when a ROCK inhibitor is administered to treat an oculardisorder, a TGF-β antagonist is also administered. In anotherembodiment, when a VEGF antagonist is administered to a subject to treatan ocular disorder, a TGF-β antagonist is also administered. In anotherembodiment of the invention, when a ROCK inhibitor and a VEGF antagonistare administered to a subject to treat an ocular disorder, a TGF-βantagonist is also administered. In ocular diseases involvingneovascularization, leakage of new blood vessels is followed by scarformation (e.g., discaform scar). The invention includes administrationof a TGF-β antagonist as well as a VEGF antagonist and a ROCK2 inhibitorto a subject to treat neovascularization in ocular disease.

Useful TGF-β antagonists include, without imitation, the following: (i)anti-TGF-β antibodies and antigen binding fragments thereof, such aspan-TGF-β antibody GC-1008 (Genzyme), anti-TGF-β₁ antibody metelimumab(CAT-192) (Cambridge Antibody Technology), and antigen binding fragmentsof those antibodies, (ii) soluble TGF-β receptors or ligand bindingfragments thereof, such as P144, a synthetic peptide encompassing aminoacids 730-743 from the membraneproximal ligand-binding domain of TGF-βtype III receptor (Esparza-López et al., 2001, J. Biol. Chem.276(18):14588-96), and a type II TGF-β receptor-Fc (IgG₁) fusion (Smith,J. et al., 1999, Circulation Res. 84:1212-22), (iii) peptides that bindto TGF-β receptors that block one or more isoforms of TGF-β, such as the25 amino acid peptides from TGF-β₁, TGF-β₂, and TGF-β₃ disclosed byHuang et al., 1997, J. Biol. Chem. 272:27155-59, that bind to TGF-βreceptors, and (iv) antisense agents that inhibit TGF-β synthesis, suchas trabedersen (Antisense Pharma GmbH), an oligonucleotide that inhibitsthe synthesis of TGF-β2. Additional antagonists are disclosed inWO2006/052568, WO 02/094833, WO 04/048382, WO 04/048381, WO 04/050659,WO 04/021989, WO 04/026871, and WO 04/026307.

In certain embodiments of the present invention, an antibody or anantigen binding fragment thereof is administered to a subject togetherwith an effective amount of a PD-L1 antibody (see U.S. 61/927,907 andPCT/US15/11657, which are incorporated herein by reference in theirentirety).

In certain embodiments, a dose of a compound or a composition isadministered to a subject every day, every other day, every couple ofdays, every third day, once a week, twice a week, three times a week, oronce every two weeks. In other embodiments, two, three or four doses ofa compound or a composition is administered to a subject every day,every couple of days, every third day, once a week or once every twoweeks. In some embodiments, a dose(s) of a compound or a composition isadministered for 2 days, 3 days, 5 days, 7 days, 14 days, or 21 days. Incertain embodiments, a dose of a compound or a composition isadministered for 1 month, 1.5 months, 2 months, 2.5 months, 3 months, 4months, 5 months, 6 months or more.

Methods of administration include but are not limited to parenteral,intradermal, intravitrial, intramuscular, intraperitoneal, intravenous,subcutaneous, intranasal, epidural, oral, sublingual, intranasal,intracerebral, intravaginal, transdermal, transmucosal, rectally, byinhalation, or topically, particularly to the ears, nose, eyes, or skin.The mode of administration is left to the discretion of thepractitioner. In most instances, administration will result in therelease of a compound into the bloodstream. For treatment of oculardisease, intravitrial administration of biological agents is preferred.

In specific embodiments, it may be desirable to administer a compoundlocally. This may be achieved, for example, and not by way oflimitation, by local infusion, topical application, by injection, bymeans of a catheter, or by means of an implant, said implant being of aporous, non-porous, or gelatinous material, including membranes, such assialastic membranes, or fibers. In such instances, administration mayselectively target a local tissue without substantial release of acompound into the bloodstream.

Pulmonary administration can also be employed, e.g., by use of aninhaler or nebulizer, and formulation with an aerosolizing agent, or viaperfusion in a fluorocarbon or synthetic pulmonary surfactant. Incertain embodiments, a compound is formulated as a suppository, withtraditional binders and vehicles such as triglycerides.

In another embodiment, a compound is delivered in a vesicle, inparticular a liposome (See Langer, 1990, Science 249:1527-1533; Treat etal., in Liposomes in the Therapy of Infectious Disease and Bacterialinfection, Lopez-Berestein and Fidler (eds.), Liss, New York, pp.353-365 (1989); Lopez Berestein, ibid., pp. 317-327; see generallyibid.).

In another embodiment, a compound is delivered in a controlled releasesystem (See, e.g., Goodson, in Medical Applications of ControlledRelease, supra, vol. 2, pp. 115-138 (1984)). Examples ofcontrolled-release systems are discussed in the review by Langer, 1990,Science 249:1527-1533 may be used. In one embodiment, a pump may be used(See Langer, supra; Sefton, 1987, CRC Crit. Ref. Biomed. Eng. 14:201;Buchwald et al., 1980, Surgery 88:507; Saudek et al., 1989, N. Engl. J.Med. 321:574). In another embodiment, polymeric materials can be used(See Medical Applications of Controlled Release, Langer and Wise (eds.),CRC Pres., Boca Raton, Fla. (1974); Controlled Drug Bioavailability,Drug Product Design and Performance, Smolen and Ball (eds.), Wiley, NewYork (1984); Ranger and Peppas, 1983, J. Macromol. Sci. Rev. Macromol.Chem. 23:61; See also Levy et al., 1985, Science 228:190; During et al.,1989, Ann. Neurol. 25:351; Howard et al., 1989, J. Neurosurg. 71:105).

The above-described administration schedules are provided forillustrative purposes only and should not be considered limiting. Aperson of ordinary skill in the art will readily understand that alldoses are within the scope of the invention.

It is to be understood and expected that variations in the principles ofinvention herein disclosed may be made by one skilled in the art and itis intended that such modifications are to be included within the scopeof the present invention.

Throughout this application, various publications are referenced. Thesepublications are hereby incorporated into this application by referencein their entireties to more fully describe the state of the art to whichthis invention pertains. The following examples further illustrate theinvention, but should not be construed to limit the scope of theinvention in any way.

EXAMPLES Example 1

Identification of Antibodies that Bind to VEGFR Domains 2 and 3 andBlock Ligand Binding.

Two antibodies that bind to and neutralize human VEGFR2, identified inTable 1, were isolated from human Fab phage display libraries. Theantibodies block binding of the ligand VEGFA to hVEGFR2 (FIG. 2). Theantibodies also bind to porcine aortic endothelial (PAE) cellsexpressing KDR, and inhibit VEGFA-stimulated phosphorylation of VEGFR2,AKT, and MAPK. (FIG. 3). Table 1 indicates amino acid sequences of theCDRs and variable domains of the antibodies. The K_(d)s of Mab 101 andMab 102 are about 6.6 mM and 1.7 nM, respectively.

The heavy chain of Mab 101 was reshuffled with κ light chain genes(κ-library) and λ light chain genes (λ-library). 20 unique λ light chainvariants were found by panning the λ-library against both human VEGFR2and mouse VEGFR2. 22 unique κ light chain variants were found by panningthe λ-library against both human VEGFR2 and mouse VEGFR2. Table 2indicates amino acid sequences of the CDRs and variable domains of thelight chains. The K_(d)s of Mabs 105, 106, and 107 were increased about10 fold (0.24 nM, 0.22 nM, and 0.12 nM, respectively) (Table 3). Theseantibodies, and antibody Mab101 from which they are derived, bind todomains 2 and 3 of VEGFR and to constructs containing those domains.

TABLE 3 Antibody Binding Data ka kd KD Antibody 10⁴M⁻¹s⁻¹ 10⁻⁴s⁻¹ nM 10755.8 0.934 0.167 109 30.6 3.80 1.24 104 79.2 1.13 0.165 110 44.9 3.100.69 108 71.9 1.75 0.244 105 24.3 0.591 0.243 101 29.8 5.93 1.81

Like the parent antibody, these antibodies bind to VEGFR2 and blockbinding of VEGFA to VEGFR2 (FIG. 4), and inhibit VEGFA-stimulatedphosphorylation of VEGFR2, AKT, and MAPK (FIG. 5).

Several of the antibodies, including Mabs 138, 139, 140, and 146, alsocross react with mouse VEGFR2.

TABLE 4 Cross Reactivity hVEGFR2 mVEGFR2 ka kd KD ka kd KD Antibody10⁴M⁻¹s⁻¹ 10⁻⁴s⁻¹ nM 10⁴M⁻¹s⁻¹ 10⁻⁴s⁻¹ nM 138 19.7 1.42 0.72 23.4 5.902.55 139 14.6 1.75 1.20 13.0 3.17 2.44 106 35.6 0.512 0.144Mabs 138, 139, and 140 inhibited VEGFA-stimulated phosphorylation ofVEFGR2 and downstream signal transduction molecules, including MAPK.

Example 2

Inhibition of Tumor Growth In Vivo

6 to 8-week-old sex-matched (female) NOD-SCID mice are irradiated with3.5 Gy from a ¹³⁷Cs gamma-ray source at a dose rate of about 0.9 Gy/minand intravenously inoculated with 2×10⁷ HL60 cells. Three days aftertumor inoculation, groups of mice are treated twice weekly with variousdoses of Mab 106 and recorded for time of survival.

All untreated mice died within about two weeks. Even with the high tumorload, the survival time for mice treatment with 10 mg/kg Mab 106 isextended to as much as 28 days.

Example 3

Treatment of Colon Cancer in a Human Patient

Human subjects diagnosed with colon cancer are divided into treatmentgroups and given the standard chemotherapeutic regimen. Two patientgroups are treated weekly with 5 mg/kg/week or 15 mg/kg/week for 4months. A control group is given only the standard chemotherapeuticregimen. Tumor burden is assessed periodically by magnetic resonanceimaging (MRI). Compared to the control group, it is expected that thepatients who have received weekly antibody treatments show significantreductions in tumor growth or tumor size, increased delay to progressionor prolonged survival compared to patients that do not receive theantibody treatment.

Mab 138 (Table 2), containing the heavy chain of Mab 101 (SEQ ID NO. 4;see FIG. 6A), was selected for affinity maturation. Mutations wereintroduced into CDR3 of the light chan and CDR1, CDR2, and CDR3 of theheavy chain. The resulting library was panned on human and murineVEGFR2. Table 5 indicates amino acid sequences of the heavy and lightchain CDRs and variable domains of five of the resulting antibodies.FIG. 6 shows a comparison of the sequences to the Mab 138 heavy chain(SEQ ID NO. 4) and kappa light chain (i.e. SEQ ID NO:160).

TABLE 5 Antibody Amino Acid Sequences by SEQ ID NO V_(H) CDR- CDR- CDR-V_(L) Mab # CDR-H1 CDR-H2 CDR-H3 domain L1 L2 L3 domain 147 197 198 199200 201 202 203 204 (B1C4_A7) 148 205 206 207 208 209 210 211 212(B1C4_H9) 149 213 214 215 216 217 218 219 220 (B1C4_E5) 150 221 222 223224 225 226 227 228 (B1C4_A6) 151 229 230 231 232 233 234 235 236(B1C4_G3)

The binding constants of Mab 147 and Mab 149 as well as the parent Mab138 for human, murine, and rat VEGFR2 were determined by Biacoreanalysis (Table 6).

TABLE 6 Biacore Analysis of Binding to Human, Murine, and Rat VEGFR2 Mabantigen k_(a) k_(d) K_(D) 138 rat 4.30E+04 1.34E−03 3.12E−08 murine2.86E+04 2.33E−03 8.17E−08 human 8.98E+04 6.00E−04 6.68E−09 147 rat6.45E+04 8.99E−04 1.39E−08 murine 4.38E+04 1.28E−03 2.94E−08 human1.13E+05 2.82E−04 2.51E−09 149 rat 3.32E+04 1.43E−03 4.31E−08 murine2.29E+04 1.81E−03 7.92E−08 human 8.62E+04 6.59E−04 7.65E−09

Mab 147 was examined by ELISA for its receptor binding and ligandblocking properties. Mab 147 binds to both soluble hVEGFR2 and solublemVEGFR2 with similar affinity (FIG. 7A). Mab 147 blocks ligand bindingto hVEGFR2 similar to a hVEGFR specific control antibody and also blocksligangd binding to mVEGFR2 similar to a mVEGFR2-specific controlantibody (FIG. 7B).

Binding of Mab 147 to hVEGFR2 and mVEGFR2 expressed on cell membraneswas also confirmed. FIG. 8A shows binding to hVEGR2 expressed by humanumbilical vein entothelial cells (HUVEC) as well as procine aorticendothelial (PAE) cells overexpressing KDR (i.e., human VEGFR2). Mab 147also bound to mVEGFR expressed by MS1 murine endothelial cells (FIG.8B).

Mab 147 inhibit VEGFR-2 mediated signal transduction, as indicated byreduced phosphorylation of KDR and p42/44 in KDR-PAE cells (FIG. 9A) andin HUVEC cells (FIG. 9B). Mab 106 and Mab 147 inhibit proliferation ofKDR-PAE cells (FIG. 10A), as well as inhibit VEGF-induced migration ofKDR-PAE cells (FIG. 10B). The effect of Mab 147 on inhibition ofVEGF-induced migration by KDR-PAE cells is also shown in FIG. 11.

Mab 147 also inhibits VEGFR-2 mediated signal transduction in murineEOMA cells, as indicated by reduced phosphorylation of mVEGFR2 (FIG.12A). FACS studies demonstrated that Mab 147 has increased binding toEOMA cells by comparison to control antibodies (FIG. 12B).

We claim:
 1. An isolated antibody or antigen binding fragment thereofthat binds to human VEGFR2, comprising a heavy chain variable domain,which comprises a CDR1H, a CDR2H, and a CDR3H sequence, and a lightchain variable domain, which comprises a CDR1L, a CDR2L, and a CDR3Lsequence wherein: (i) the CDR1H sequence is GFTFSWYVMG (SEQ ID NO: 237);(ii) the CDR2H sequence is SIYPQGGATSYADSVKG (SEQ ID NO: 238); (iii) theCDR3H sequence is GNYFDY (SEQ ID NO: 241); (iv) the CDR1L sequence isRASQSVSSNYFG (SEQ ID NO: 245); (v) the CDR2L sequence is GASSRAT (SEQ IDNO: 246); and (vi) the CDR3L sequence is QQFDSLPLT (SEQ ID NO: 247). 2.The antibody or antigen binding fragment of claim 1, wherein the heavychain variable domain has a sequence that is SEQ ID NO: 200, and whereinthe light chain variable domain has a sequence that is SEQ ID NO: 204.3. The antibody or antigen binding fragment of claim 1, which hasisotype IgG.
 4. The antibody or antigen binding fragment of claim 1,which is an scFv, Fv, Fab′, Fab, F(ab′)2, or diabody.
 5. The antibody orantigen binding fragment of claim 1, wherein the antibody or antigenbinding fragment binds to human VEGFR2 and murine hVEGFR2.
 6. Theantibody or antigen binding fragment of claim 1, wherein the heavy chainvariable domain has a sequence that is at least 85% identical to thesequence of SEQ ID NO: 200, and wherein the light chain variable domainhas a sequence that is at least 85% identical to the sequence of SEQ IDNO:
 204. 7. A composition comprising an antibody or antigen bindingfragment of claim 1, and a pharmaceutically acceptable carrier.
 8. Amethod of neutralizing activation of human VEGFR2 or murine VEGFR2comprising contacting a cell with an effective amount of an antibody orantigen binding fragment of claim
 1. 9. A method of inhibitingangiogenesis associated with tumor growth in a subject in need thereof,the method comprising administering to the subject an effective amountof an antibody or antigen binding fragment of claim
 1. 10. A method ofreducing tumor growth in a subject in need thereof, the methodcomprising administering to the subject an effective amount of anantibody or antigen binding fragment of claim
 1. 11. The method of claim10, the method further comprising administering to the subject anantineoplastic agent.
 12. The method of claim 10, the method furthercomprising administering to the subject an anti-inflammatory agent or animmunosuppressant.
 13. A method of treating a neoplastic disease in asubject, the method comprising administering to the subject an effectiveamount of an antibody or antigen binding fragment of claim 1, whereinthe neoplastic diseases is selected from the group consisting of lungcancer, colorectal cancer, renal cell carcinoma, glioblastoma, ovariancancer, bladder cancer, gastric cancer, multiple myeloma, non-small celllung cancer, and pancreatic cancer.